The Wiehen Hills (German: Wiehengebirge, also locally, just Wiehen) are a hill range in North Rhine-Westphalia and Lower Saxony in Germany. The hills run from west to east like a long finger away from the main upland area of the Lower Saxon Hills, beginning at the Weser River near Minden and terminating in the vicinity of Osnabrück. It is the northernmost of the German Central Upland ranges extending into the Northern Lowlands. Their highest hill is the Heidbrink near Lübbecke with an altitude of 320 metres (1,050 ft).
The Wiehen Hills lie within the districts of Osnabrück, Minden-Lübbecke and Herford. Their northern section runs in an east-west direction roughly from the territory of Bramsche (northwest of Osnabrück) via Ostercappeln, Bad Essen, Preußisch Oldendorf and Rödinghausen, Lübbecke, Hüllhorst and Bad Oeynhausen as far as the towns of Minden and Porta Westfalica on the Porta Westfalica gorge and River Weser. They also graze Bohmte and Hille to the north. South of the Wiehen Hills lie Osnabrück, Bissendorf, Melle, Kirchlengern, Bünde, Löhne and Bad Oeynhausen. The Wiehen Hills form the northwestern boundary of the Lower Saxon Hills to which they belong geographically, together with the Westphalian part of the ridge. Whilst the eastern end of the hill chain is clearly defined by the Porta Westfalica gorge and the hill of Wittekindsberg, this is not so simple for its western extremity. To the west the Wiehen descends gradually, transitioning from a hilly ridge into a chain of hillocks and then descending almost imperceptibly into the plain. South of Bramsche the ridge rises again at the Penter Egge to a height of 99 metre, but 2.5 km further west it reaches the level of the surrounding countryside. The waterways of the Mittelland Canal and Osnabrück Canal running away to the south appear to mark the end of the hill range, but west of these canals is the 82 metre high Larberger Egge which forms the westernmost cornerstone of the Wiehen Hills, rising just 2 km northeast of the boundary with the province of Münster. Contrary to popular assumption, Ibbenbüren is no longer considered to be situated by the Wiehen Hills and the Ibbenbüren Plateau (Ibbenbürener Bergplatte comprising the Schafberg, etc.) is no longer part of the Wiehen. Geological reasons, according to current research, do not support such an assumption.